TW202132016A - Optical sensor window cleaner - Google Patents

Abstract

A sensor assembly includes a passageway for a process fluid, an optical window, an optical sensor, and a nozzle. The optical sensor configured to detect an optical property of the process fluid. The optical window includes an inner surface. The nozzle configured discharge an atomized fluid in a discharge direction that intersects the inner surface of the optical window. A sensor system includes a sensor assembly and conduits for supplying a gas and a liquid to a nozzle of the sensor assembly. A method of cleaning an optical window in a sensor assembly includes forming an atomized fluid and discharging the atomized fluid in a discharge direction that intersects the optical window.

Description

Optical sensor window cleaner

The present invention relates to a sensor for measuring fluid properties. More specifically, the present invention relates to an optical sensor for measuring the optical properties of a flowing fluid.

The optical sensor can be used to determine one or more properties of the flowing fluid. The optical sensor can transmit light to the fluid through the window. Light can be refracted at the boundary between the window and the fluid. The optical sensor can determine the refractive index of the fluid by detecting the amount, angle, or amount and angle of light refracted by the fluid. The refractive index of the fluid can be used to determine other properties of the fluid. For example, the refractive index of the fluid can be used to determine the concentration or purity of the fluid. The process fluid may include liquid or a mixture of liquid and solid.

The sensor system includes a sensor assembly and a conduit for supplying process fluid to the sensor assembly. The sensor assembly includes a channel for the process fluid, an optical window, and an optical sensor. The optical window forms the side wall of the passage. The process fluid flows through the channel and contacts the optical window. The sensor is configured to transmit light through the optical window and detect the optical properties of the process fluid.

Embodiments of a sensor system, a sensor assembly, and a method for cleaning optical windows are disclosed. In an embodiment, the sensor system includes a sensor assembly. The process fluid is supplied to the sensor assembly. In some embodiments, the sensor assembly includes an optical window and an optical sensor for detecting the optical properties of the process fluid.

In one embodiment, the sensor system includes a sensor assembly and a fluid circuit (for example, pipes, pipes, pipes, combinations thereof, etc.) for supplying process fluids, liquids, and gases to the sensor assembly. The sensor assembly includes channels for process fluids, optical windows and nozzles. The optical window forms the sidewall of the via and the process fluid contacts the optical window. The fluid circuit is fluidly connected to the nozzle to supply liquid. The fluid circuit is also fluidly connected to the nozzle to supply gas. The nozzle is configured to discharge atomized fluid including liquid and gas in the direction of impacting the inner surface of the optical window. The atomized fluid impacts and removes materials that can scatter light.

In one embodiment, the sensor assembly includes a channel for process fluid, an optical window, and a nozzle. The optical window forms the sidewall of the passage, and the process fluid is configured to contact the optical window. The nozzle is configured to form and discharge atomized fluid including liquid and gas in the direction of impacting the inner surface of the optical window.

In one embodiment, the method of cleaning the optical window in the sensor assembly includes atomizing liquid and gas. The sensor assembly includes a channel for the process fluid, an optical window, and an optical sensor for the process fluid. The atomized fluid is discharged into the passage in the direction of impacting the optical window.

As used in this specification and the scope of the appended application, the singular forms "a", "an" and "the" include plural referents, unless the content clearly indicates otherwise. As used in this specification and the scope of the appended application, the term "or" is usually used in its meaning including "and/or", unless the content clearly indicates otherwise.

The term "about" usually refers to a range of values that is considered equivalent to the stated value (for example, having the same function or result). In many cases, the term "about" can include numbers rounded to the nearest significant figure.

Numerical ranges expressed using endpoints include all values falling within the range (for example, 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

The following embodiments should be read with reference to the drawings, in which similar elements in different drawings are denoted by the same reference numerals. The embodiments and drawings (which are not necessarily to scale) describe illustrative examples and are not intended to limit the scope of the present invention. The illustrative embodiments described are to be regarded as illustrative only. Selected features of any illustrative embodiment can be combined into additional embodiments, unless clearly stated to the contrary.

The optical sensor can be used to detect one or more optical properties of the fluid. The fluid can be directed to flow along one side of the optical window, while the optical sensor is positioned along the other side of the window. The optical sensor can be configured to transmit light through the optical window and detect how the fluid affects the light. For example, the optical sensor can be configured to detect how light is refracted at the transition area between the optical window and the flowing fluid. For example, the optical sensor can be configured to detect the amount of light reflected by the flowing fluid. The optical properties of the process fluid can be used to determine one or more other properties of the process fluid, such as the concentration or purity of the process fluid.

The components of the fluid can be attracted to the optical window and deposited on the optical window, thereby forming a material layer on the optical window. The attraction and deposition of the component to the optical window can be caused by, for example, the intermolecular force between the component and the material of the optical window (for example, the zeta potential of the component can drive them toward the optical window, and once they are close to each other, the attraction is caused by Van der Waals force drive). This problem may occur more obviously when the fluid includes solid particles that are more likely to adhere to the optical window. In addition, it has been found that over time, deposits become more difficult to remove. Therefore, the longer the particles stay on the optical window, the more intense the particle deposition and the more difficult it is to remove.

Those skilled in the art will recognize that part of the material layer on the optical window may adversely affect the propagation of light and produce erroneous measurements. In sensors that rely on high-precision measurement, such as in semiconductor manufacturing, this error may have a significant adverse effect in the semiconductor manufacturing process.

The embodiments disclosed herein are related to a sensor assembly, a sensor system, and a method of cleaning the optical window in the sensor assembly. As used herein, cleaning an optical window may include, for example, removing deposited components from the optical window to at least partially expose the surface of the optical window. The sensor system may include a sensor assembly. The embodiments described herein can discharge atomized fluid at the optical window to remove most to all of any material deposited on the optical window. Atomizing the liquid to discharge the atomized fluid can accelerate the liquid portion of the atomized fluid and cause cavitation on the surface (for example, after impacting the optical window, the droplets of the liquid portion of the atomized fluid implode). Without being bound by theory, it is believed that the impact of droplets of the liquid portion of the atomized fluid on the optical window can trigger a shock wave, thereby removing deposits or materials from the optical window.

FIG. 1 is a schematic diagram of an embodiment of the sensor system 1. 1 by the sensor system comprises a sensor configured to one or more optical properties of _a detector assembly 10 the process fluid F. In one embodiment, the sensor assembly 10 detects the refractive index of the _{process fluid F 1.}

The sensor assembly 10 includes a passage 12, an optical window 32, an optical sensor 38 and a nozzle 50. The passage 12 includes an inlet 20 and an outlet 22. The passage 12 extends through the sensor assembly 12 from the inlet 20 to the outlet 22. The process fluid F ₁ flows through the sensor assembly 10 by flowing through the passage 12. The process fluid F ₁ flows in through the inlet 20, flows through the passage 12, and then flows out through the outlet 22 to flow through the sensor assembly 10.

The first conduit 60 supplies the process fluid F ₁ to the inlet 20 of the passage 12. The first conduit 60 fluidly connects the process fluid source 62 to the inlet 20. The process fluid F ₁ flows from the source 62 of the process fluid to the passage 12 through the first conduit 60. In one embodiment, the process fluid source 62 may be a tank _{containing the process fluid F 1.} In one embodiment, the process fluid source 62 may be based receiving process fluid F plurality of tank components of the _one, and the process fluid source 62 mix these ingredients to form a process fluid F _1, then a first conduit 60 supplies the process fluid . The first conduit 60 includes a flow valve 64. The flow valve 64 controls the flow rate f _{1 of the process fluid F 1} supplied from the first conduit 60 to the passage 12 and the sensor assembly 10. In one embodiment, the flow valve 64 is controlled by the controller 90. The controller 90 is configured to adjust the flow valve 64 to control the flow rate f _{1 of the process fluid F 1} flowing to and through the sensor assembly 10.

In one embodiment, the process fluid F ₁ for polishing a semiconductor wafer in semiconductor manufacturing. The process fluid F ₁ contains liquid and abrasive particles. In one embodiment, the abrasive particles include one or more of ceria, colloidal silica, fumed silica, and lanthanum fluoride. In one embodiment, the process fluid F ₁ contains at least 0.1 wt.% abrasive particles. In one embodiment, the process fluid F ₁ contains about 0.1 wt.% to about 30 wt.% of abrasive particles. In one embodiment, the process for the liquid fluid F can comprise water or _a water-based solution.

When flowing through the channel 12 from the inlet 20 to the outlet 22, the process fluid F ₁ flows along the optical window 32. The optical sensor 38 is positioned along the optical window 32. The optical sensor 38 transmits light to the passage 12 through the optical window 32. The optical sensor 38 is also detected by the light refraction of _a process fluid F. The optical sensor 38 is configured to detect the _{refractive index of the process fluid F 1} by detecting the light refracted by the process fluid F ₁ .

The nozzle 50 can clean the optical window 32. The nozzle 50 forms an atomized fluid 52 and discharges the atomized fluid 52 to the optical window 32. The atomized fluid 52 impacts the optical window 32 and is configured to remove the material deposited on the optical window 32. In one embodiment, the nozzle 50 may be referred to as an air jet or air-assisted atomizer. The operation of the nozzle 50 is discussed in more detail below. The atomizing fluid 52 contains liquid F ₂ and gas F ₃ . The second duct 70 supplies the liquid F ₂ to the nozzle 50 and the third duct 80 supplies the gas F ₃ to the nozzle 50. The nozzle 50 is configured to combine the liquid F ₂ and the gas F ₃ to form an atomized fluid 52.

The second pipe 70 is fluidly connected to the nozzle 50 and _{supplies the liquid F 2} to the nozzle 50. In one embodiment, the liquid F ₂ includes one or more of water, ammonium hydroxide, and liquid low-pollutant semiconductor manufacturing cleaning products (for example, PlanarClean AG-Ce1000K, ESC 784 cleaning solution, etc.). In one embodiment, water is deionized ("DI") water. In one embodiment, the second conduit 70 fluidly connects the liquid source 72 to the nozzle 50. In an embodiment, the liquid source 72 includes a filter and/or one or more tanks _{containing the liquid F 2.} In one embodiment, the liquid source 72 is a filter that produces DI water.

The second conduit 70 includes a flow valve 74 and a flow sensor 76. The flow valve 74 controls the flow rate f _{2 of the liquid F 2} supplied to the nozzle 50. The flow sensor 76 detects the flow rate f _{2 of the liquid F 2 that} passes through the second conduit 70 and is supplied to the nozzle 50. In one embodiment, the controller 90 controls the flow valve 74. The controller 90 can control the flow rate f _{2 of the liquid F 2} supplied to the nozzle 50 within a specific amount or a specific range as discussed below. The controller 90 can use the flow sensor 76 to detect the flow rate f _{2 of the liquid F 2} supplied to the nozzle 50.

The third conduit 80 is fluidly connected to the nozzle 50 and _{supplies pressurized gas F 3} to the nozzle 50. In one embodiment, a gas comprising F ₃ or more inert gases and clean dry air (CDA). In an embodiment, the gas F ₃ is an inert gas, which may include, but is not limited to, one or more of nitrogen, helium, neon, argon, krypton, xenon, and the like. In one embodiment, the nitrogen-based gas F _3. In one embodiment, the first conduit 80 fluidly connects the gas source 82 to the nozzle 50. In one embodiment, the gas source 82 comprises a filter and a gas receiving one or more of F _3, one or both of the tanks. In one embodiment, the gas source 82 is a filter that generates purified nitrogen and/or argon from the air.

The conduit 80 includes a flow valve 84 and a flow sensor 86. The flow valve 84 controls the flow rate f _{3 of the gas F 3} supplied to the nozzle 50. The flow sensor 86 detects the flow rate f _{3 of the gas F 3} supplied to the nozzle 50 through the conduit 80. In one embodiment, the controller 90 controls the flow valve 84. The controller 90 can control the flow rate f _{3 of the gas F 3} supplied to the nozzle 50 within a specific amount or a specific range as discussed below. The controller 90 can use the flow sensor 86 to detect the flow rate f _{3 of the gas F 3} supplied to the nozzle 50.

FIG. 2 is a cross-sectional view of an embodiment of the sensor assembly 10. The sensor assembly 10 includes a passage 12 with an inlet 20 and an outlet 22, an optical window 32, an optical sensor 38, a nozzle 50, a second conduit 70 _{for liquid F 2} and a third conduit _{for gas F 3} 80.

The process fluid F ₁ flows through the sensor assembly 10 by flowing through the passage 12. The passage 12 extends from the inlet 20 to the outlet 22. The process fluid F ₁ is configured to flow in through the inlet 20 and flow out through the outlet 22. The optical window 32 and the nozzle 50 are each positioned along the passage 12.

The optical window 32 forms the side wall 14 of the passage 12. The optical window 32 includes an inner surface 34 and an outer surface 36. The outer surface 36 is opposite to the inner surface 34. In one embodiment, the inner surface 34 of the optical window 32 forms the side wall 14 of the passage 12. When flowing through the passage 12, the process fluid F ₁ contacts the inner surface 34 of the optical window 32. The inner surface 34 of the optical window 32 is made of scratch-resistant material. In one embodiment, the inner surface 34 of the optical window 32 is made of diamond or sapphire. In one embodiment, the inner surface 34 of the optical window 32 is made of borosilicate glass.

The optical sensor 38 is connected to the optical window 32. In one embodiment, the optical sensor 38 is attached to the outer surface 36 of the optical window 32. The optical sensor 38 is configured to transmit light through the optical window 32 and detect the light transmitted to the optical sensor 38 in the optical window 32. For example, optical sensor 38 to the passage 32 may transmit light in a direction D _1. The optical sensor 38 is configured to detect the light refracted _{by the process fluid F 1 at the inner surface 34.} The detected light refraction can then be used to determine the refractive index of the _{process fluid F 1.}

The pipe 70 and the pipe 80 _{supply the liquid F 2} and the gas F ₃ to the nozzle 50. The nozzle 50 discharges the atomized fluid 52 of the _{liquid F 2} and the gas F _{3 into the passage 12.} The atomized fluid 52 is discharged through the opening 18 in the second side wall 16 of the passage 12. In one embodiment, the second side wall 16 is opposite to the first side wall 14. In an embodiment, the second side wall 16 is formed by the nozzle 50. In one embodiment, the atomizing fluid 52, the liquid F ₂ and the gas F ₃ do not flow in through the inlet 20 of the passage 12. The atomized fluid 52 is discharged at the inner surface 34 of the optical window 32. The nozzle 50 discharges the atomized fluid 52 in a direction impacting the inner surface 34 of the optical window 32. In an embodiment, the direction of the atomized fluid 52 may be referred to as the discharge direction D ₂ . In one embodiment, the discharge direction D ₂ intersects the inner surface 34 of the optical window 32. In one embodiment, the discharge direction D _{2 is} perpendicular to the inner surface 34 of the optical window 32.

Similarly as discussed above, when the process fluid F ₁ flows and shrinks along the inner surface 34 of the optical window 32, the material accumulates on the inner surface 34 of the optical window 32. In one embodiment _{, the solid abrasive particles in the process fluid F 1} adhere and accumulate on the inner surface 34 of the optical window 32.

The nozzle 50 is configured to discharge the atomized fluid 52 at the optical window 32 at a high speed. The configuration and operation of the nozzle 50 will be discussed in more detail below. _{The liquid F 2} droplets in the atomized fluid 52 impact the inner surface 34 of the optical window 32 at a high speed. In one embodiment, each high-speed impact generates a liquid shock wave that propagates outward along the inner surface 34 from the impact point. The liquid shock wave exerts a shearing force, which removes the accumulated material on the inner surface. In one embodiment, the high-speed impact of the droplet on the optical window 32 causes cavitation at the point of impact. Cavitation is also used to remove any material adhering to the inner surface 34 of the optical window 32. In one embodiment, the atomized fluid 52 can remove most to almost all materials adhered to the inner surface 34 of the optical window 32. In one embodiment, the liquid _{selected for the liquid F 2} can establish a favorable zeta potential (eg, repulsion versus attraction), which can prevent debris and particles from reattaching to the inner surface 34 of the optical window 32, for example.

In an embodiment, the discharge direction may be different from perpendicular to the inner surface 34. In one embodiment, the nozzle 50 may be configured to D ₄ in the discharge direction 52 on the atomizing fluid is discharged, the discharge direction D ₄ D ₃ within 45 degrees of a direction, perpendicular to the direction D ₃ of the optical window 32内surface34. For example, the nozzle 50 may be configured to discharge the atomized fluid 52 such that the angle α between the _{discharge direction D 4 and the direction D 3} perpendicular to the inner surface 34 is less than 45 degrees. It should be understood that those skilled in the art will understand that with knowledge of the content of the present invention, the discharge direction D ₄ may be selected to achieve the desired cleaning effect.

In FIG. 2, the nozzle 50 and the passage 12 are separate components, and the nozzle 50 is connected to the thread 24. However, it should be understood that the nozzle 50 in an embodiment can be connected in different ways, such as but not limited to clamping, welding, machining together, appropriate combinations thereof, and the like. In one embodiment, the passage 12 and the nozzle 50 may be a single continuous component.

FIG. 3 is an enlarged view of the nozzle 50, the duct 70, and the duct 80. FIG. As described above, the pipe 70 and the pipe 80 respectively supply the liquid F ₂ and the gas F ₃ to the nozzle 50. In one embodiment, the nozzle 50 includes a chamber 59 for forming an atomized fluid 52 _{from the liquid F 2} and the gas F _3.

The nozzle 50 includes an inner channel 54 and a first inlet 58A _{for the liquid F 2.} The second conduit 70 is connected to the first inlet 58A and _{supplies the liquid F 2} to the first inlet 58A of the nozzle 50. The first inlet 58A is fluidly connected to the inner passage 54. The liquid F ₂ flows from the second duct 70 to the inner passage 54 via the first inlet 58A. The liquid F ₂ flows through the inner channel 54 and enters the chamber 59.

It includes an outer nozzle 50 and the passage 56 for the gas inlet 58B F ₃ of a second. The second duct 80 is connected to the second inlet 58B and _{supplies the gas F 3} to the second inlet 58B of the nozzle 50. The second inlet 58B is fluidly connected to the outer passage 56. The gas F ₃ flows from the duct 80 to the outer passage 56 via the second inlet 58B. The gas F ₃ flows through the outer passage 56 and enters the chamber 59.

The outer channel 56 surrounds the inner channel 54. The inner passage 54 has an end 55 located at the cavity 59. The end 55 is opposite to the first inlet 58A. In one embodiment, the outer channel 56 is concentric with the first channel 56 at the end 55 of the inner channel 54. The liquid F ₂ flows into the chamber 59 from the inner channel 54, and the gas F ₃ flows into the chamber 59 from the outer channel 56.

The gas F ₃ flows out of the outer channel 56 and mixes _{with the liquid F 2 in the chamber 59.} When mixed into the liquid F _2, F ₃ gas dispersion liquid into droplets F ₂ and F ₂ accelerate liquid droplets. In one embodiment, the gas F ₃ flowing out of the outer channel 56 has a greater velocity _{than the liquid F 2} flowing out of the inner channel 54. The atomized fluid 52 is then discharged from the chamber 59 through the opening 18 of the nozzle 50 _{in the discharge direction D 2.} In one embodiment, the discharge direction D ₂ is the direction of the average velocity of the atomized fluid 52 at the opening 18.

In one embodiment, all the liquid F ₂ and gas F ₃ supplied to the nozzle 50 are discharged. The atomized fluid 52 cleans the optical window 32. The nozzle 50 is operated by controlling the flow rate f ₂ and the flow rate f ₃ of the liquid F ₂ and the gas F ₃ supplied to the nozzle 50. In one embodiment, as discussed above, the flow valve 74 and the flow valve 84 (shown in FIG. 1) control the flow rate f ₂ and the flow rate f _{3 of the liquid F 2} and the gas F ₃ flowing to the nozzle 50. In one embodiment, the flow valve 74 and the flow valve 84 are closed to stop the cleaning of the optical window 32 by the nozzle 50. In one embodiment, the optical window 32 is cleaned by opening both the valve 74 and the valve 84. In one embodiment, the controller 90 is configured to only start cleaning when the valve 64 _{for the process fluid F 1 is closed.}

When the optical window 32 needs to be cleaned, the flow valve 74 and the flow valve 84 are opened so that the liquid F ₂ and the gas F ₃ reach the nozzle 50. The nozzle 50 then discharges the atomized fluid 52 at the inner surface 34 of the optical window 32, which cleans the inner surface 34 of the optical window 32. In one embodiment, the atomized fluid 52 contains 20% or about 20% or less than 20% of liquid F ₂ by volume. In one embodiment, the atomized fluid 52 contains 0.65% or about 0.65% or less than 0.65% of liquid F ₂ by volume. In one embodiment, the atomized fluid 52 contains 0.02% or about 0.02% or more than 0.02% of liquid F ₂ by volume. In one embodiment, the atomized fluid 52 contains 0.15% or about 0.15% or more than 0.15% of liquid F ₂ by volume. In one embodiment, the atomized fluid 52 contains about 0.02% to 20% liquid F ₂ by volume.

In one embodiment, when the optical window 32 is cleaned, the second duct 70 supplies about 0.5 liters to 2 liters per minute (LPM) of liquid F ₂ to the nozzle 50. In one embodiment, when the optical window 32 is cleaned, the third duct 80 supplies approximately 10 standard liters to 300 standard liters per minute (SLPM) of gas F ₃ to the nozzle 50. In one embodiment, the liquid fraction f ilk ₂ F ₂ F ₃ ilk gas rate ratio f ₃ (f _2: f ₃₎ based from about 0.05: 300 to about 2:10. In one embodiment, the controller 90 may be configured to regulate the flow valve 74, flow valve 84, so that the flow rate of liquid F ₂ and F ₃ of F ₂ gas, the flow rate f ₃ is supplied to the nozzle 50. In an embodiment, the controller 90 may be configured to close the flow valve 74 and the flow valve 84 when the _{process fluid F 1 flows in through the passage 12.}

FIG. 4 is a block diagram of an embodiment of a method 100 for cleaning an optical window in a sensor assembly. For example, the method 100 can be used to clean the optical window 32 in the sensor assembly 10 in FIGS. 1 to 3. In an embodiment, the optical window 32 may be a part of a sensor system (for example, the sensor system 1). The method starts at 110.

At 110, a process fluid stream (e.g., process fluid F ₁ ) is supplied to a passage (e.g., passage 12) of a sensor assembly (e.g., sensor assembly 10). The sensor assembly includes a passage, an optical window (for example, the optical window 32), and an optical sensor (for example, the optical sensor 38). The optical sensor is configured to transmit light to the channel through the optical window to detect the optical properties of the fluid. The process fluid contacts the optical window as it flows through the via. Then, the method 100 proceeds to 120.

At 120, the process fluid flow to the channel is stopped. In one embodiment, a flow valve (e.g., flow valve 64) controls the process fluid flow. In one embodiment, stopping the process fluid flow (120) may include closing a flow valve. Then, the method 100 proceeds to 130.

At 130, an atomized fluid (eg, atomized fluid 52) containing gas (eg, gas F ₃ ) and liquid (eg, liquid F _{2) is formed.} In one embodiment, forming the atomized fluid (130) includes supplying a liquid stream to a nozzle (132) (e.g., nozzle 50). In one embodiment, the liquid is supplied to the nozzle through a conduit (for example, conduit 70). The conduit may supply liquid to the inlet of the nozzle (for example, the first inlet 58A). In one embodiment, forming the atomized fluid (130) includes supplying a gas stream to the nozzle 134. In one embodiment, the gas is supplied to the nozzle through a second conduit (for example, conduit 80). The conduit may supply gas to the second inlet (for example, the second inlet 58B).

In one embodiment, forming the atomized fluid 130 also includes combining the liquid flow and the gas flow in the nozzle (136). The liquid stream and the gas stream are combined to form an atomized fluid. In one embodiment, the nozzle includes a chamber (e.g., chamber 59). The liquid flow and the flowing gas flow each flow into the chamber and are combined in the chamber. Then, the method 100 proceeds from 130 to 140.

At 140, the atomized fluid is discharged into the passage through the nozzle. The atomized fluid is discharged in the discharge direction (for example, the discharge direction D ₂ ) intersecting with the inner surface 34 of the optical window 32. The droplets in the atomized fluid are configured to impact the inner surface 34 at a high speed. The material adhering to the inner surface 34 of the optical window 32 is removed by the high-speed impact of the droplets.

In an embodiment, the method 100 may be modified based on the sensor system 1 as shown in FIG. 1 or as described above, or the sensor assembly 1 as shown in FIGS. 1 to 3 or as described above . For example, the method 100 may include stopping the supply of liquid with a valve. Appearance:

Any one of aspects 1 to 7 can be combined with any one of aspects 8-19, and any one of aspects 8-15 can be combined with any one of aspects 16-19.

Aspect 1. A sensor assembly comprising: a passage for a process fluid to flow through the sensor assembly; an optical window including an inner surface of a first part of a side wall forming the passage; an optical sensor, which It is configured to transmit light to the channel through the optical window to detect the optical properties of the process fluid; and a nozzle, which is used to discharge liquid and gas in the form of atomized fluid into the channel in the direction of impacting the inner surface of the optical window.

Aspect 2. The sensor assembly of aspect 1, wherein the atomized fluid is discharged into the channel through the opening in the second part of the side wall of the channel.

Aspect 3. The sensor assembly of aspect 2, wherein the first part of the side wall and the second part of the side wall are arranged on opposite sides in the passage.

Aspect 4. The sensor assembly of any one of aspects 1 to 3, wherein the angle between the discharge direction and the direction perpendicular to the inner surface of the optical window is less than 45 degrees.

Aspect 5. The sensor assembly of any one of aspects 1 to 4, wherein the nozzle includes an outer channel for gas and an inner channel for liquid, the outer channel surrounds the inner channel, and the nozzle combines the gas with The liquids combine to form an atomized fluid.

Aspect 6. The sensor assembly of any one of aspects 1 to 5, wherein the atomized fluid contains about 0.05 to 20% liquid by volume.

Aspect 7. The sensor assembly of any one of aspects 1 to 6, wherein the liquid system is deionized water and the gas system is an inert gas.

Aspect 8. A sensor system, comprising: a sensor assembly for a process fluid, the sensor assembly including: a passage for the process fluid to flow through the sensor assembly; An optical window on the inner surface of the side wall; an optical sensor configured to transmit light to the passage through the optical window to detect the optical properties of the process fluid, used to form a nozzle containing liquid and gas atomized fluid, the nozzle passes Configured to discharge the atomized fluid into the passage in the direction of impacting the inner surface of the optical window; fluidly connect to the nozzle to supply liquid to the first conduit of the nozzle; and fluidly connect to the nozzle to supply gas The second conduit to the nozzle.

Aspect 9. The sensor system of aspect 8, wherein the process fluid contacts the inner surface of the optical window.

Aspect 10. The sensor system of one of aspects 8 or 9, wherein the atomized fluid is discharged into the channel through an opening in the side wall of the channel.

Aspect 11. The sensor system of aspect 10, wherein the opening in the side wall of the passage and the optical window are arranged on the opposite side of the passage.

Aspect 12. The sensor system of any one of aspects 8 to 11, wherein the nozzle includes an outer channel and an inner channel, the outer channel surrounds the inner channel, and the first conduit supplies the liquid to the inner channel of the nozzle And the second conduit supplies gas to the channel outside the nozzle.

Aspect 13. The sensor system of any one of aspects 8 to 12, wherein the first conduit supplies the flow rate of the liquid to the nozzle and the second conduit supplies the flow rate of the gas to the nozzle, so that the atomized fluid contains It is about 0.02% to 20% liquid by volume.

Aspect 14. The sensor system of any one of aspects 8 to 13, wherein the first conduit supplies the flow rate of the liquid to the nozzle and the second conduit supplies the flow rate of the gas to the nozzle, and the flow rate of the liquid is The ratio of the volume of the gas is from 0.05:300 to 2:10.

Aspect 15. The sensor system of any one of aspects 8 to 14, further comprising: a first flow valve, which controls the flow of liquid to the nozzle through the first conduit; and a second flow valve, which controls the flow of gas through The flow rate of the second conduit to the nozzle; and a controller configured to close the first flow valve and the second flow valve when the process fluid flows into the passage.

Aspect 16. A method of cleaning an optical window in a sensor assembly, the sensor assembly includes a channel and an optical sensor, the optical sensor transmits light to the channel through the optical window to detect the flow through the channel For the optical properties of the process fluid, the method includes: forming an atomized fluid containing gas and liquid; and discharging the atomized fluid into the passage in the direction of impacting the inner surface of the optical window.

Aspect 17. The method of aspect 16, wherein forming the atomized fluid includes: supplying a liquid stream to the nozzle, supplying a gas stream to the nozzle, and mixing the liquid stream and the gas stream in the nozzle.

Aspect 18. The method of one of aspects 16 or 17, wherein expelling the atomized fluid into the passage in a direction impacting the inner surface of the optical window includes guiding the atomized fluid through the side wall of the passage in the direction The opening.

Aspect 19. The method of any one of aspects 16 to 18, further comprising: supplying the process fluid stream to the channel; and stopping the flow of the process fluid into the channel before discharging the atomized fluid into the channel.

Having described several illustrative embodiments of the present invention in this way, those skilled in the art will easily understand that other embodiments can be manufactured and used within the scope of the attached patent application. In the foregoing description, many advantages of the disclosure covered by this document have been explained. However, it should be understood that the present invention is merely illustrative in many respects. The details can be changed, especially the shape, size and configuration of the components, without going beyond the scope of the present invention. Of course, the scope of the present invention is limited by the language expressed in the scope of the attached patent application.

1: Sensor system 10: Sensor assembly 12: Passage 14: First side wall 16: Second side wall 18: Opening 20: Inlet 22: Outlet 24: Thread 32: Optical window 34: Inner surface 36: Outer surface 38: optical sensor 50: nozzle 52: atomizing fluid 54: inner channel 55: end 56: outer channel 58A: first inlet 58B: second inlet 59: chamber 60: first conduit 62: process fluid source 64: Flow valve 70: Second conduit 72: Liquid source 74: Flow valve 76: Flow sensor 80: Third conduit 82: Gas source 84: Flow valve 86: Flow sensor 90: Controller 100: Method 110 : Step 120: Step 130: Step 132: Step 134: Step 136: Step 140: Step D ₁ : Direction D ₂ : Discharge Direction D ₃ : Direction D ₄ : Discharge Direction F ₁ : Process Fluid F ₂ : Liquid F ₃ : Gas ƒ ₂ : Flow rate ƒ ₃ : Flow rate α: Angle

The description and other features, aspects and advantages of the sensor system, the sensor assembly, and the method of cleaning the optical window in the sensor assembly will be better understood with the following diagrams:

Figure 1 is a schematic diagram of an embodiment of the sensor system.

FIG. 2 is a cross-sectional view of the sensor assembly in FIG. 1 according to an embodiment of the present invention.

Fig. 3 is an enlarged cross-sectional view of the nozzle in Fig. 2 according to an embodiment of the present invention.

FIG. 4 is a block diagram of an embodiment of a method of cleaning the optical window in the sensor assembly.

Although the present invention can have various modifications and alternative forms, its details have been shown by examples in the drawings and will be described in detail. However, it should be understood that the intention is not to limit the aspects of the invention to the specific illustrative embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and replacements falling within the spirit and scope of the present invention.

10: Sensor assembly

12: Access

14: The first side wall

16: second side wall

18: opening

20: entrance

22: Exit

24: Thread

32: Optical window

34: inner surface

36: Outer surface

38: optical sensor

50: nozzle

52: Atomized fluid

70: second catheter

80: third duct

D ₁ : direction

D ₂ : Discharge direction

D ₃ : direction

D ₄ : Discharge direction

F ₁ : Process fluid

F ₂ : Liquid

F ₃ : Gas

α: Angle

Claims (10)

A sensor assembly, which includes: A passage for a process fluid to flow through the sensor assembly; An optical window including an inner surface forming a first part of a side wall of the passage; An optical sensor configured to transmit light to the passage through the optical window to detect an optical property of the process fluid; and A nozzle for discharging a liquid and a gas in the form of an atomized fluid into the passage in a direction that impacts the inner surface of the optical window. The sensor assembly of claim 1, wherein the atomized fluid is discharged into the passage through an opening in a second part of the side wall of the passage. The sensor assembly of claim 1, wherein an angle between the ejection direction and a direction perpendicular to the inner surface of the optical window is less than 45 degrees. The sensor assembly of claim 1, wherein the nozzle includes an outer channel for the gas and an inner channel for the liquid, the outer channel surrounds the inner channel, and the nozzle uses the gas and the The liquids combine to form the atomized fluid. A sensor system, which includes: A sensor assembly for a process fluid, the sensor assembly includes: A passage for the process fluid to flow through the sensor assembly; An optical window having an inner surface forming a side wall of the passage; An optical sensor configured to transmit light to the passage through the optical window to detect an optical property of the process fluid, and A nozzle for forming an atomized fluid containing a liquid and a gas, and the nozzle is configured to discharge the atomized fluid into the passage in a direction that impacts the inner surface of the optical window; A first pipe fluidly connected to the nozzle to supply the liquid to the nozzle; and A second conduit is fluidly connected to the nozzle to supply the gas to the nozzle. The sensor system of claim 5, wherein the process fluid contacts the inner surface of the optical window. The sensor system of claim 5, wherein the atomized fluid is discharged into the passage through an opening in the side wall of the passage. The sensor system of claim 5, wherein the nozzle includes an outer channel and an inner channel, the outer channel surrounds the inner channel, the first conduit supplies the liquid to the inner channel of the nozzle, and the second conduit The gas is supplied to the outer passage of the nozzle. Such as the sensor system of claim 5, which further includes: A first flow valve that controls the flow of the liquid to the nozzle through the first conduit; A second flow valve that controls the flow of the gas to the nozzle through the second conduit; and A controller configured to close the first flow valve and the second flow valve when the process fluid flows into the passage. A method of cleaning an optical window in a sensor assembly, the method comprising: A process fluid flows through a passage of a sensor assembly. The sensor assembly includes an optical sensor that transmits light to a passage through the optical window to detect the flow through the passage One of the optical properties of the process fluid; Forming an atomized fluid containing a gas and a liquid; and The atomized fluid is discharged into the passage in a direction that impacts an inner surface of the optical window.

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